Protesters have taken to the streets in Tanzania for a third day, defying warnings from the country's army chief to end the unrest.
Demonstrations have been taking place in major cities with young protesters denouncing Wednesday's election as unfair as key opposition figures were excluded from contesting against President Samia Suluhu Hassan.
An internet shutdown remains in place, making it difficult to confirm reports of deaths, and the authorities have extended a curfew in a bid to quell the protests.
The UN has called on the East African nation's security forces to refrain from using unnecessary or disproportionate force.
"We are alarmed by the deaths and injuries that have occurred in the ongoing election-related protests in Tanzania. Reports we have received indicate that at least 10 people were killed," Reuters quoted the UN human rights spokesperson Seif Magango as saying, citing "credible sources".
Amnesty International in Kenya told the BBC that with communications down in neighbouring Tanzania the rights group was not able to confirm reports of deaths.
Hospitals in the country are refusing to give information to journalists or human rights groups when asked about causalities.
The government has sought to play down the scale of the violence.
The electoral commission has announced results from more than half of the country's total 100 constituencies, the state broadcaster, TBC, shows.
President Samia is expected to win the vote under the ruling Chama Cha Mapinduzi (CCM) party, which has governed the country since independence in 1961.
Official results are expected on Saturday.
Tanzania's chief Muslim cleric - Sheikh Abubakar Zubeir bin Ally - has urged Muslims to perform Friday prayers at home amid fears of escalating violence.
On Thursday, army chief Gen Jacob John Mkunda ordered the protesters off the streets, saying the military would work with other security agencies to contain the situation.
"Some people went to the streets on 29 October and committed criminal acts. These are criminals and the criminal acts should be stopped immediately," Gen Mkunda said on state TV, adding that the army had "controlled the situation".
But the protesters have again taken to the streets of the commercial capital, Dar es Salaam.
On Tanzania's semi-autonomous archipelago of Zanzibar - which elects its own government and leader - the CCM's Hussein Mwinyi, who is the incumbent president, has won with nearly 80% of the vote.
The opposition in Zanzibar said there had been "massive fraud", the AP news agency reported.
Tourists on the archipelago are also reported to be stranded at the airport, with flight delays because of the protests, which have been on the mainland.
The protesters accuse the government of undermining democracy, as the main opposition leader is in jail and another opposition figure was disqualified from the election, bolstering Samia's chances of winning.
Tundu Lissu, the main opposition leader, is in jail on treason charges, which he denies, and his party boycotted the vote.
The only other serious contender, Luhaga Mpina of the ACT-Wazalendo party, was disqualified on legal technicalities.
Sixteen fringe parties, none of whom have historically had significant public support, were cleared to contest the elections.
Samia took office in 2021 as Tanzania's first female president following the death of President John Magufuli.
She was initially praised for easing political repression, but the political space has since narrowed, with her government accused of targeting critics through arrests and a wave of abductions.
